I started with a 3D scan of me wearing the costume using my wife's iPhone when the first version with LIDAR came out. After cleaning up the scan (iPhone 12 LIDAR wasn't the best quality) in Blender, I spent a good many hours in Xlights placing every single light at its correct 3D position using the imported mesh as a reference. Laborious work, but with all 1300-odd WS2811 LEDs mapped in all 3 axes, it makes for a pretty beautiful product.
Using Xlights is great. For open source it's pretty smooth. There's a small learning curve for the technology, but making sequences a strong resemblance to video editing. The project has frequest updates, I haven't seen any project-breaking format changes in the 3.5 years I've used it, and it's clearly maintained by people who use it. Push new rendered sequences to my FPP-running raspi on the costume through wifi then editing the running playlist through a web interface on FPP on the laptop is a dream.
If anyone's curious:
FPP: https://github.com/FalconChristmas/fpp
My dreamcoat sequenced to Holst's Jupiter: https://www.youtube.com/watch?v=ZWzdUJsAMa4&pp=ygUNbGVkIGRyZ...
Timelapses of me making the costume: https://www.youtube.com/watch?v=PODWVIsqwwA&pp=ygUNbGVkIGRyZ...